137 Mhz

QHA is designed for 137mhz frequency in cst.simulation result shown the s11 paremeter at 480mhz.but the radiation pattern comes good at 137mhz.how to get return loss at 137mhz
give me suggestions on how to feed an qha antenna?reply me my design feed port is defined at the (...)

I'm looking to try to make an antenna to cover the range 118-137mhz. The constraints are basically
diameter < 20 mm.
Length, certainly less than 700 mm, but even that might not be possible. I think something in the range 300-500 mm is more likely to be acceptable
SWR < 2:1.
Power handling 20 W.
Fed at the base - it can't be centre fed.

i'm now still design LNA for weather satellite reception (137.5 mhz). some friends, suggest me to use multisim...but i cant simulate it..
i have been review many design about this LNA (maybe ten, i found in web), but i'm still confuse how to simulate it..
i have been build the model in Multisim, but when i simulate it i cant get good data

hi Guys...
im will design LNA for weather satellite (137mhz)..if i googling in the web it many design of this LNA...and mostly is only single stage and common-source configuration...
why it doesnt design by differential or cascode....
is it any advantages or disadvantages of both model...?
i have been read in wikipedia that cascode i

Hello,
I´m trying to modify a Philips SAA7215HS with an SDI (Serial Digital Interface) output. Pins 128, 131-137 are data lines and the pin 126 is the 27 mhz clock to sync the signal.
I have noise in the sync line and need to "clean it". I have try a 100ohm resistor in sync line and a 27-47cp Cap. from ground to sync but doesn´t work.
Any